Dig out the drainage ditch. Broaden the ditch to roughly twice the width of the culvert and angle the sides of the ditch. Dig about six inches out of the bottom, for the entire length of the culvert.
Fill the bottom six inches with gravel, maintaining the original level of the drainage ditch. The gravel will allow the culvert to settle evenly and allow for better drainage in the event that water flows around the culvert.
Place the culvert in the ditch, centering it in the gravel. There should be about one foot of excess length on each end of the culvert.
Fill in the sides next to the culvert with dirt, tamping the dirt down at regular intervals. Keep the culvert centered in the ditch while doing this; a crooked culvert will cause erosion on the walls of the ditch.
Cover the top of the culvert. Cover with at least 12 inches of dirt and tamp down well. Cover this with gravel to avoid erosion.
Tamp the sides of the fill down tightly, making sure they are angled in towards the top. Regular maintenance will be needed to keep the walls from eroding away.
Things You Will Need
- Fill dirt
- Use one large culvert, rather than several small ones. Several small culverts are harder to maintain and allow for more erosion.